Tube cutting machine



April 23, 1946.

'A. FORSBERG TUBE CUTTING MACHINE Filed July .20, 1944 z sheets shet 1 INVENTOR 4M, WMw ATTORNEYS.

April 1946- D. A. FORSBERG TUBE.CUTTING MACHINE Filed July 20, 1944 2 Sheets-Sheet 2 INVE NTOR P545527 6. Fbzsesa;

I BY

ATTDRNEV5.

Patented Apr. 23, 1946 UNITED STATES OFF-ICE 'ronnioocr'rmo MAGHINE -Delbert A}; Forsberg, Madison, Wis. I v Application July e0, 1944, Serial No. 545,377

13- Claims.

This invention relates to improvements in tube cutting machines.

The objects of the invention are to improve and accelerate tube cutting operations, to pro vide for uniformity of operation of the cutting knives, both as to pressure, depth of cut and speed; to eliminate the need of experienced operators; to facilitate the discharge of cut cores from the mandrel; to promote safety in the use of the equipment; and to provide apparatus for achieving the foregoing objectives which can be attached to existing standard tube cutting machines to improve their functioning in the particulars specified. I

Other objects will be apparent to those skilled in the art upon analysis of the following disclosure.

In the drawings: 7 Fig. 1 is a view principally in front elevatio and partially broken away of a tube cut-ting'machine embodying my invention.

Fig. 2 is a detail view taken in section on the line 22 of Fig. 1.

Fig. 3 is a detail View taken in section on the line 33 of Fig. 1. V

Fig. 4 is afragmentary plan view of a portion of the apparatus shown in Fig. 1, with parts broken away to expose underlying structure.

Like parts are identified by the same reference characters throughout the several views.

The tube cutting machine illustrated as a means of exemplifying the invention is fundamentally of conventional design. Such machines conventionally include parts corresponding to the frame 5, drive shaft and pulley 6, 1, mandrel 8, retractable mandrel bearing 9, the tiltable plate l upon which the carriers H are adjustable for the support of the disk knives [2, the lever IS, the linkage 6 to the tiltable plate 10,; and the linkage [7, bell crank l8 and link 19 to the tiltable tail stock 2!] for the retractable mandrel bearing 9.

In the use of conventional machines comprising the foregoing elements, it took considerable skill to exert exactly the right amount of pressure on the knives to sever the tube on the mandrelwithout blunting the edges of the knives against the mandrel or cutting into the mandrel. A dextrous operator could perform many more operations in a given period than a less dextrous operator, even though the latter had the skill enabling him to know the right amount of pressure to use.

safety and to enable even themo'st unskilled operator safely and expeditiously to operate the machine, I have proivde'cl means for mechanical- 1y performing the requisite operations, and eohtrols which require the use or both hands of the operator at positions keeping them from the danger zone.

From the central portion of the frame, Is-uspend a sub-frame 22 upon which. is mounteda motor 23'- operatively connected through reduction gearing Hand. clutch .25 to drive .a cam shaft 26 which carries a cam 2] andis constantlysubject to the drag of afriction brake shoeat 28. The clutch25 is ofthe type, .well known commercially whichis disengaged when a stop member such as thatshown at 29 encounters a lug 30 on the exterior of the clutch. When the stop lever 29 is pivoted out ofengagement with the lug 3D, the clutch automatically engagesto complete a. driving connection to the cam shaft. 1

Pivoted on arm 31 is a. cam follower lever 32 supporting the cam follower roller 33 in peripheralengagementwith the cam 21. A link 34 having a turn buckle 35 for adjusting its length, connects the "cam follower lever 32,with the-conventional operating lever 15 ofthe machine. In lieu of a spring to hold the cam follower roller 33 in peripheral engagement with cam'fl, reliance is placed on the biasing weight with which thetail stock '20 is conventionally jprovided,such weight acting constantly: to tend to tilt the tailstock 20 pivotally about its fulcrum at 37; The bias is transmitted through the bell crank l8,--lever ll to lever 15. When the high part of cam 21 engages: theroller'33, it actuate's the lever I5 in opposition to the bias of weight as to :lift the. tail stock 20, v 9 with the mandrel 8 and to: bring the knives 1'2 into operative cutting engagement with the core tube on the mandrel B. The adjustment afforded by the turn buckle. at 35 provides a very precise control of the operation of these parts in the course of rotation of thecam 21. The rate of rotation of the cam shaft 25 and'cam I? determines the period of time, required for the cutting operation and the adjustment determines the depth of out.

The lever 29 which effects engagementland dis,- engagement of the clutch 25 has an operating handle projecting upward-1y at 42. Thelever is fulcrumed at 43 on a bracket attached to the In order to eliminate the need for -skilland* dexterity and inorder, moreover, to promote back of the frame. The handle must be pulled forwardly slightlyto-disengage the stopleverf28.

from block 30. As soon as clearancefor'thelug to engage the bearing tracted tg'iltlietleftag ainst the 'biasof spring so which tends' 'to draw the slide into stop position in the path of web49. The slide is moved to the left to retract it from the path of web 49 by means of a manually operable stripping sleeve55 on the mandrel and an arm 56 notched to receive the mandrel and disposed in the path of the stripping sleeve 55, such arm being mounted on a plate51 carried by the slide 45, as best shown in Figs. 3 and 4. The stripping sleeve has a handle at 58 from which depends a rod 59 which, engaging the bed of the frame, keeps the sleeve 55from rotatingwith the mandrel at such times as the operator does nothappen to be using the handle 58.'

When the uncut core tube'is slid on t the end of mandrel 8 exposed by the retraction of bearing 9; the stripping sleeve 55 must be moved ahead of the core tube toward the left, as viewed in Fig, 2, Where it ultimately contacts the notched arm 55. At this point, the entire length of the' core tube 49 is on the mandrel, leaving clearance at the endof the mandrel for engagement of the mandrel by the tail stock bearing 9. The stripping sleeve is not, however, at the extreme limit of its leftward movement, being yieldably precluded from advance to its extreme left position by the bias of spring 50 which, acting on the slide, yieldabl positions the notched arm 56 with which the stripping sleeve 55 is engaged.

In order that the machine may function'to slit or cut the core tube 40', the operator is required to grasp the handle 58 with his left hand and the handle 42 with his right hand. When the operator pushes handle 58 to the left, the sleeve 55 will thrust arm 56 and slide 46 to the left against spring 50, thus removing the stop end of slide 46 from thelpath of the web 49 on lever 42; The operator can now pull the handle 42 forwardly to release stop lever 29 from the clutch lug 30, thereby engaging'the clutch; The operator may then' release both of the handles 42 and 58. The handle 42 will be drawn by spring to a position where it will disengage the clutch upon the completion ofone Icam shaftrotation. Thereupon the slide 4Ewill-be pulled to the right, as viewed in Figs. 2 and 4, into the path of web 49 to prevent any further movement of handle 42 until the above sequence of operations is repeated.

Meantime the engagement of the clutch is causing one 'full rotation of the cam shaft 25 which, almost instantly, will swing the-tail stock bearing 9 intoengagement with the free end of the mandrel and simultaneouslyraise the knives. to out the core tube to precisely the correct depth and WiILthereupon, withdraw the-knives and retract the tail stock bearing.

Using the stripping sleeve by means of handle 58 (afeature valuable independently of the cutting control), the operator will now eject. the out cores from mandrelil by sliding thesleeve the lengthof the mandreland forcing the cores from the end thereof. A new core tube is immediately pla'ced'onthe mandrel, the stripping sleev 55 being simultaneously returned and the sequence ofoperations is then repeated. The mandrel will The motor 23 and the drive through the reduction gearing at 24 as far as the clutch i also in continuous operation while the machine is in use. The drag brake at 28 prevents overrun of the cam shaft and arrests cam shaft movement promptly upon the completion of one rotation.

Since the operator i required to use both hands to withdraw the stop slide 46 and to actuate the clutch engaging lever, and since the cutting knives move into engagement with the work and out again before the operator can release these parts and move his hands into danger, the machine is safe as well as speedy by reason of the attachments described.

, I claim:

1. In a core tube cutting machine including a 'mandrel and knife means movable to and from engagement with work on the mandrel, the combination with actuating connections for such knife means, of a constantly operating driving motor, a driven operator for said connections, a clutch subject to manual control for coupling said motor with said operator and provided with means for clutch disengagement after a predetermined operation of said operator, and manual control means for engaging the clutch, said operator and connections being adapted to move the knife a cam rotatably mounted and in operative association with the cam follower and manually controllable means for rotating said cam for ne revolution, said cam being contoured to actuate said lever in the course of such cam revolution for the advance of the knife means and the retraction thereof.

3. In a device of the character described having a mandrel and knife means movable to and from the mandrel, the combination with actuating connections for said knife means including a rotatable part and mechanism for advancing and retracting the knife means in a single complete cycle in the course of a single part rotation, a clutch controlling part rotation and including means for mechanically disengaging the clutch upon the completion of a single rotation of said part, means for manually initiating the clutch controlled part rotation, and a continuously operable source of power in driving relation through the clutch to said part.

4. The device of claim 3 in which said clutch has a clutch disengaging lug and the manual control means for the-clutch includes a stop normally disposed in the path of said lug and manually displaceable therefrom, whereby displacement of the stop will release the lug and release of the stop will-occasion the reengagement of the lug to disengage the clutch upon the completion of one rotation of said part.

5. In a device of the character described including a mandrel, a knife support movable to and from the mandrel, and knife means 'on said support, the combination with actuating connections for said support, of rotatable means for operating said connections to move said support' from a normally retracted position to operative cutting relation to work on the mandrel and thence back to said position, and means for actuating said rotatable means and comprising a motor, a clutch, and means for engaging said clutch for a single rotation, said motor having a driving connection through said clutch to said rotatable means.

6. In a device of the character described including a mandrel, a knife support movable to and from the mandrel, and knife means on said support, the combination with actuating connections for said support, of rotatable means for operating said connections to move said support from a normally retracted position to operative cutting relation to work on the mandrel and thence back to said position, and means for actuating said rotatable means and comprising a motor, a clutch, and means for engaging said clutch for a single rotation, said motor having a driving connection through said clutch to said rotatable means, together with a hand lever for the actuation of said clutch, releasing means, and a stop having a separate handle and disposed in the path of said hand lever whereby said stop must be moved by the operator coincidentally with the actuation of said hand lever as a prerequisite to clutch engagement.

7. In a machine of the character described having a mandrel, a knife support movable to and from the mandrel, and knife means on the support for engagement with work on the mandrel, and a lever provided with a link connection to said support for the actuation thereof, the combination with a driving motor and driving connections therefrom including a normally disengaged clutch, of means connected to be driven through said clutch for the oscillation of said lever through a given cycle of forth and back movement, and means for manually engaging said clutch for a single rotation.

8. The device of claim 7 in which said clutch has a stop lug and said clutch engaging means comprises a lever having a stop portion biased for movement into the path of said lug and removable therefrom to permit the release of said lug for the engagement of the clutch, a detent normally in the path of oscillation of said lever and movable from said path whereby the movement of the detent is a prerequisite to the operation of the lever for the engagement of said clutch, and a sleeve on the mandrel, said detent having means engaged by the sleeve for moving said detent from thepath of lever movement, said sleeve being provided with a handle.

9. In a device of the character described having a mandrel, a knife support and knife means on the support, the combination with the mandrel, of a stripping sleeve mounted thereon for axial movement and provided with a handle fixed thereto, and means for preventing sleeve rotation with said mandrel, whereby said handle is accessible during manual rotation.

10. In a device of the character described having a mandrel, a knife support and knife means on the support, the combination with the mandrel, of a stripping sleeve mounted thereon for axial movement and provided with a handle,

together with mechanical actuating connections provided with a manual control for advancing the knives toward the mandrel and retracting the knives therefrom, said manual control having a detent normally precluding its operation, and retracting means for the detent disposed in the path of the stripping sleeve to be actuated thereby, whereby a movement of the stripping sleeve is a prerequisite to the actuation through said manual control of the connections for advancing and retracting the knife means. 7

11. In a device of the character described including a mandrel, a knife support and knife means movable on said support to and from the mandrel, the combination with the mandrel, of a stripping sleeve mounted thereon and movable axially of the mandrel, a handle for the operation of the stripping sleeve, a retractable detent, means for transmitting motion from the stripping sleeve to the detent for the retraction of the detent, a manually operable control mounted for movement across the path of the detent whereby to be inoperable pending detent retraction, and mechanical operating connections for the'knife support including a clutch engageable subject to said manual control.

12. A device of the character described comprising a motor, a clutch having a peripheral clutch disengaging lug, a manually retractable stop in the path of said lug for clutch disengagement, a cam connected to receive motion from said motor through said clutch when the clutch is engaged, a cam follower, an adjustable link connected with said cam follower, a knife movable to and from work engagement, and connections from saidlink for the actuation of said knife into and from work engagement in the course of cam rotation, the range of knife movement being predetermined by the adjustment of said link.

13. In a device of the character described having a mandrel, a knife support, knife means on the support movable to and from the mandrel, and an actuating lever in operative connection with said knife support, the combination of a hand lever provided with a fulcrum and a handle portion projecting above said mandrel, a detent in the path of said hand lever comprising a slide reciprocable in substantial parallelism with the mandrel, an arm connected with said slide and notched to receive the mandrel, a stripping sleeve upon the mandrel provided with a handle and engageable with said arm for the retraction of said detent, means for biasing said detent against retraction by said sleeve, a motor adapted for continuous operation, driving connections from the motor including a clutch having a peripheral clutch disengaging lug with which said hand lever is normally in contact, said lever being movable to release said look upon the retraction of said detent, a cam operatively connected to receive motion from said driving connections through said clutch when said clutch is engaged, a cam follower biased to peripheral engagement with the cam, and means including an adjustable link connecting said cam follower with the lever which operates the knife support.

DELBERT A. FORSBERG. 

